President Obama speaks on the situation in Ukraine on the South Lawn of the White House on March 20, 2014. / Mandel Ngan, AFP/Getty Images

by Aamer Madhani, USA TODAY

by Aamer Madhani, USA TODAY

WASHINGTON - President Obama announced Thursday that he is levying additional sanctions against 20 high-level Russian officials and associates of Russia President Vladimir Putin as well as a bank in response to Moscow's move to annex the Crimea region of Ukraine.

Obama spoke just hours after Russia's lower parliament ratified a treaty to make Crimea a part of the Russian Federation. Crimeans voted overwhelmingly in a hastily arranged referendum this week to join Russia.

The White House has repeatedly called the referendum and Russia's action "illegal."

"This is not our preferred outcome," Obama said in a statement from the South Lawn of the White House. "These sanctions would not only have a significant impact on the Russian economy, but could also be disruptive to the global economy. However, Russia must know that further escalation will only isolate it further from the international community."

Russia immediately retaliated, announcing shortly after Obama spoke that it was imposing its own entry bans on nine White House aides and members of Congress in response to the sanctions announced by Obama. The Russian list includes House Speaker John Boehner, Senate Foreign Relations Chairman Robert Menendez, D-N.J., and Sen. John McCain, R-Ariz., as well as Obama aides Dan Pfeiffer and Ben Rhodes.

"The speaker is proud to be included on a list of those willing to stand against Putin's aggression," said Michael Steel, a Boehner spokesman.

Under the new sanctions announced by the White House, any assets that the individuals have in U.S. jurisdiction have been frozen and Americans are prohibited from doing business with them.

Obama said that he also signed a new executive order Thursday that gives the United States authority to impose sanctions not just on individuals but on "key sectors of the Russian economy." The new order gives the Treasury Department the ability to target individuals and institutions in Russia's financial services, energy, metals and mining, defense and engineering sectors

The new round of sanctions follow Obama's announcement this week that he was targeting seven Russian officials with close ties to Putin as well as four Ukrainians that the White House says have contributed to the crisis in Ukraine.

Among those identified by the Treasury Department as targets Thursday are several who have deep ties to Putin.

Andrei Fursenko, an aide to Putin, has been close to the Russian president for more than 20 years. Vladimir Yakunin, who is chairman of the board of the Russian state-owned company Russian Railways. were neighbors in an elite dacha community on the shore of Lake Komsomolsk and served together as co-founders of the Ozero Dacha Cooperative in November 1996.

Four members of what the Treasury Department described as members of Russia's "inner circle" were also among those targeted.

The inner circle targets include Gennady Timchenko, one of the founders of the world's largest independent commodity trading companies in the oil and energy markets; Yuri Kovalchuk, the single-biggest shareholder of Bank Rossiya and the personal banker to Putin and other senior Russian officials; and Arkady Rotenberg and Boris Rotenberg, oligarchs and brothers who received approximately $7 billion in contracts for the Sochi Olympic Games.

The Bank Rossiya, which is the personal bank of many senior Russian officials and whose shareholders include many in Putin's inner circle, was also named.

After the White House named the first round of targets this week, several Russian officials mocked the punitive measure as meaningless because they had no assets in the United States.

With Thursday's announcement, the Treasury Department argued that the sanctions have teeth and will severely limit some Russian oligarchs' ability to do business outside of Russia.

"With its currency near an all-time low, its stock market down 20% this year and a marked rise in interest rates, Russia has already started to bear the economic costs of its unlawful effort to undermine Ukraine's security, stability and sovereignty," said David Cohen, the Treasury Department's undersecretary for Terrorism and Financial Intelligence.

Obama said in an interview on Wednesday that there is currently no military option being considered to respond to Russia's action.

"But what we can do is stand up for principle, stand by the Ukrainian people," Obama told KSDK-TV.

Obama will meet with leaders of the Group of Eight - minus Russia - next week in the Netherlands to discuss the situation in Ukraine. The meeting will occur on the margins of the biennial Nuclear Security Summit.

British Prime Minister David Cameron on Wednesday said the leaders should discuss expelling Russia from the G-8.

Even as Obama announced the sanctions, he expressed hope for a diplomatic end to the crisis.

"The Russian people need to know, and Mr. Putin needs to understand, that the Ukrainians shouldn't have to choose between the West and Russia," Obama said. "We want the Ukrainian people to determine their own destiny, and to have good relations with the United States, with Russia, with Europe, with anyone that they choose."